<span>It is usually the + strand and the - strand. It can be quite a bit more complicated.</span>
Answer:
Proteins is a macromolecule that helps to send signals
Answer:
The correct option is H) these acids change the environment.
Explanation:
Soil can be described as the part of the environment where plants grow. In primary succession, life stars arising in an area which has no soil and only rocks, This is possible because lichens are the organisms which can grow on the rocks. Lichens secrete certain acids which break down these rocks and hence soil begins to form when these rocks break. This makes it possible for other plant species to grow on these lands.
Answer:
<u>d. Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.
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Explanation:
Solutes are typically moved across the cell through either passive or active transport. The cells, surrounded by a bilipid layer or plasma membrane is amphiphlic- its polar, hydrophilic lipid heads face outwards, while their non-polar hydrophobic lipid tails face inwards towards each other.
While lipid-soluble molecules move across the layer easily, it is also difficult for charged and also large molecules to move across its surface, into the cell. Transmembrane channels, <u>embedded within the membrane</u>, help to maintain selective permeability as transport proteins, pores and gated channels. Simple diffusion happens as a method of passive transport in cells through plasma membranes.
The solutes travel through the plasma membrane in the process of diffusion from regions of high concentration to regions of low concentration; this occurs without the use of energy. <u>Molecules moving against their concentration require active transport mechanism to cross the membrane</u>.
